GATE AE topic:compressible-flows PYQs & Answers — Page 3

Questions 21–30 of 41. Imported answers require independent review unless marked reviewed.

In a converging duct, area and velocity at section P are 1 m

and 15 m/s, respectively. The temperature of the fluid is 300 K.

Air flow through the nozzle can be assumed to be inviscid and isothermal. Characteristic gas constant is 287 J/(kg-K) and ratio of specific heats is 1.4 for air.

To ensure that the air flow remains incompressible (Mach number,

) in the duct, the minimum area required at section Q is ____ m

(rounded off to two decimal places).

Diagram for Aerospace Engineering question 53

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

A convergent-divergent nozzle with adiabatic walls is designed for an exit Mach number of 2.3. It is discharging air to atmosphere under the conditions indicated in the figure.

Flow through the nozzle is inviscid, the characteristic gas constant for air is 287 J/(kg-K), and

When the reservoir pressure is 25 bar (absolute), and temperature is 300 K, Prandtl-Meyer expansion waves appear at the nozzle exit as shown.

The minimum percentage change in the reservoir pressure required to eliminate the wave system at the nozzle exit under steady state is ______ %.

Diagram for Aerospace Engineering question 55

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

The figure shows schematics of wave patterns at the exit of nozzles A and B operating at different pressure ratios.

Diagram for Aerospace Engineering question 4

Nozzles A and B, respectively, are said to be operating in:

Your answerChoose one option.

over-expanded mode and under-expanded mode

under-expanded mode and perfectly expanded mode

perfectly expanded mode and under-expanded mode

under-expanded mode and over-expanded mode

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

The shape of a supersonic diffuser that slows down a supersonic flow to subsonic flow is

Your answerChoose one option.

converging

diverging

diverging–converging

converging–diverging

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

Which of the following statement(s) is/are true across an oblique shock (in adiabatic conditions) over a wedge shown below?

Diagram for Aerospace Engineering question 14

Your answerSelect all correct options. You can choose more than one.

Total pressure decreases

Mach number based on velocity tangential to the shock decreases

Total temperature remains constant

Mach number based on velocity tangential to the shock remains the same and that based on velocity normal to the shock decreases

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

A shock moving into a stationary gas can be transformed to a stationary shock by a change in reference frame, as shown in the figure. Which of the following is/are true relating the flow properties in the two reference frames?

Diagram for Aerospace Engineering question 33

Your answerSelect all correct options. You can choose more than one.

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

Which of the following options can result in an increase in the Mach number of a supersonic flow in a duct?

Your answerChoose one option.

Increasing the length of the duct

Adding heat to the flow

Removing heat from the flow

Inserting a convergent-divergent section with the same cross-sectional area at its inlet and exit planes

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

A wedge shaped airfoil is placed in a supersonic flow as shown in the figure (not to scale). The corners of the wedge are at

, respectively. Which one of the following represents the correct static pressure profiles along

and

Diagram for Aerospace Engineering question 27

Your answerChoose one option.

Diagram for Aerospace Engineering question 27 (figure 2)

Diagram for Aerospace Engineering question 27 (figure 3)

Diagram for Aerospace Engineering question 27 (figure 4)

Diagram for Aerospace Engineering question 27 (figure 5)

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

An oblique shock is inclined at an angle of 35 degrees to the upstream flow of velocity 517.56 m/s. The deflection of the flow due to this shock is 5.75 degrees and the temperature downstream is 182.46 K. Assume the gas constant

J/(kg K), specific heat ratio

, and specific heat at constant pressure

J/(kg K). Using conservation relations, the Mach number of the upstream flow can be obtained as ______ (round off to one decimal place).

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

For a quasi-one-dimensional isentropic supersonic flow through a diverging duct, which of the following is true in the direction of the flow?

Your answerChoose one option.

Both the Mach number and the static temperature increase.

The Mach number increases and the static temperature decreases.

The Mach number decreases and the static temperature increases.

Both the Mach number and the static temperature decrease.

You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answer

GATE AE topic:compressible-flows PYQs

Question 53

Question 55

Question 4

Question 9

Question 14

Question 33

Question 8

Question 27

Question 39

Question 6